From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ED15ECE560 for ; Mon, 24 Sep 2018 16:25:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F249F2087A for ; Mon, 24 Sep 2018 16:25:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F249F2087A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730741AbeIXW2W (ORCPT ); Mon, 24 Sep 2018 18:28:22 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:43008 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726400AbeIXW2W (ORCPT ); Mon, 24 Sep 2018 18:28:22 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w8OGNfBm043285 for ; Mon, 24 Sep 2018 12:25:25 -0400 Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mq202vh6g-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 24 Sep 2018 12:25:24 -0400 Received: from localhost by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 24 Sep 2018 10:25:19 -0600 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w8OGPGrw51576958 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 24 Sep 2018 09:25:16 -0700 Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5D51CBE053; Mon, 24 Sep 2018 10:25:16 -0600 (MDT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D1531BE056; Mon, 24 Sep 2018 10:25:12 -0600 (MDT) Received: from oc8043147753.ibm.com (unknown [9.85.130.123]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Mon, 24 Sep 2018 10:25:12 -0600 (MDT) Subject: Re: [PATCH v10 24/26] KVM: s390: device attrs to enable/disable AP interpretation To: David Hildenbrand , Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com, frankja@linux.ibm.com References: <1536781396-13601-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1536781396-13601-25-git-send-email-akrowiak@linux.vnet.ibm.com> <9263b698-1827-1b7f-28bf-75b44657dea2@redhat.com> <18a21cda-1da9-3bfb-7b34-80415b5457f9@linux.ibm.com> <172560fb-2c54-ea43-3401-f108cf2a0595@redhat.com> From: Tony Krowiak Date: Mon, 24 Sep 2018 12:25:12 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <172560fb-2c54-ea43-3401-f108cf2a0595@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18092416-0012-0000-0000-000016BADB43 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009763; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000267; SDB=6.01093025; UDB=6.00564895; IPR=6.00873062; MB=3.00023484; MTD=3.00000008; XFM=3.00000015; UTC=2018-09-24 16:25:22 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18092416-0013-0000-0000-00005484A51C Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-24_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1809240161 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/24/2018 07:23 AM, David Hildenbrand wrote: > On 22/09/2018 01:40, Tony Krowiak wrote: >> On 09/17/2018 04:51 AM, David Hildenbrand wrote: >>> Am 12.09.18 um 21:43 schrieb Tony Krowiak: >>>> From: Tony Krowiak >>>> >>>> Introduces two new VM crypto device attributes (KVM_S390_VM_CRYPTO) >>>> to enable or disable AP instruction interpretation from userspace >>>> via the KVM_SET_DEVICE_ATTR ioctl: >>>> >>>> * The KVM_S390_VM_CRYPTO_ENABLE_APIE attribute enables hardware >>>> interpretation of AP instructions executed on the guest. >>>> >>>> * The KVM_S390_VM_CRYPTO_DISABLE_APIE attribute disables hardware >>>> interpretation of AP instructions executed on the guest. In this >>>> case the instructions will be intercepted and pass through to >>>> the guest. >>>> >>>> Signed-off-by: Tony Krowiak >>>> --- >>>> arch/s390/include/asm/kvm_host.h | 1 + >>>> arch/s390/include/uapi/asm/kvm.h | 2 ++ >>>> arch/s390/kvm/kvm-s390.c | 27 +++++++++++++++++++++++---- >>>> 3 files changed, 26 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >>>> index b32bd1b..36d3531 100644 >>>> --- a/arch/s390/include/asm/kvm_host.h >>>> +++ b/arch/s390/include/asm/kvm_host.h >>>> @@ -719,6 +719,7 @@ struct kvm_s390_crypto { >>>> __u32 crycbd; >>>> __u8 aes_kw; >>>> __u8 dea_kw; >>>> + __u8 apie; >>>> }; >>>> >>>> #define APCB0_MASK_SIZE 1 >>>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >>>> index 8c23afc..a8dbd90 100644 >>>> --- a/arch/s390/include/uapi/asm/kvm.h >>>> +++ b/arch/s390/include/uapi/asm/kvm.h >>>> @@ -161,6 +161,8 @@ struct kvm_s390_vm_cpu_subfunc { >>>> #define KVM_S390_VM_CRYPTO_ENABLE_DEA_KW 1 >>>> #define KVM_S390_VM_CRYPTO_DISABLE_AES_KW 2 >>>> #define KVM_S390_VM_CRYPTO_DISABLE_DEA_KW 3 >>>> +#define KVM_S390_VM_CRYPTO_ENABLE_APIE 4 >>>> +#define KVM_S390_VM_CRYPTO_DISABLE_APIE 5 >>>> >>>> /* kvm attributes for migration mode */ >>>> #define KVM_S390_VM_MIGRATION_STOP 0 >>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>>> index 2cdd980..286c2e0 100644 >>>> --- a/arch/s390/kvm/kvm-s390.c >>>> +++ b/arch/s390/kvm/kvm-s390.c >>>> @@ -856,12 +856,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm) >>>> >>>> static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) >>>> { >>>> - if (!test_kvm_facility(kvm, 76)) >>>> - return -EINVAL; >>>> - >>>> mutex_lock(&kvm->lock); >>>> switch (attr->attr) { >>>> case KVM_S390_VM_CRYPTO_ENABLE_AES_KW: >>>> + if (!test_kvm_facility(kvm, 76)) >>>> + return -EINVAL; >>>> get_random_bytes( >>>> kvm->arch.crypto.crycb->aes_wrapping_key_mask, >>>> sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask)); >>>> @@ -869,6 +868,8 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) >>>> VM_EVENT(kvm, 3, "%s", "ENABLE: AES keywrapping support"); >>>> break; >>>> case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW: >>>> + if (!test_kvm_facility(kvm, 76)) >>>> + return -EINVAL; >>>> get_random_bytes( >>>> kvm->arch.crypto.crycb->dea_wrapping_key_mask, >>>> sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask)); >>>> @@ -876,17 +877,31 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) >>>> VM_EVENT(kvm, 3, "%s", "ENABLE: DEA keywrapping support"); >>>> break; >>>> case KVM_S390_VM_CRYPTO_DISABLE_AES_KW: >>>> + if (!test_kvm_facility(kvm, 76)) >>>> + return -EINVAL; >>>> kvm->arch.crypto.aes_kw = 0; >>>> memset(kvm->arch.crypto.crycb->aes_wrapping_key_mask, 0, >>>> sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask)); >>>> VM_EVENT(kvm, 3, "%s", "DISABLE: AES keywrapping support"); >>>> break; >>>> case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW: >>>> + if (!test_kvm_facility(kvm, 76)) >>>> + return -EINVAL; >>>> kvm->arch.crypto.dea_kw = 0; >>>> memset(kvm->arch.crypto.crycb->dea_wrapping_key_mask, 0, >>>> sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask)); >>>> VM_EVENT(kvm, 3, "%s", "DISABLE: DEA keywrapping support"); >>>> break; >>>> + case KVM_S390_VM_CRYPTO_ENABLE_APIE: >>>> + if (!ap_instructions_available()) { >>>> + mutex_unlock(&kvm->lock); >>>> + return -EOPNOTSUPP; >>>> + } >>>> + kvm->arch.crypto.apie = 1; >>>> + break; >>>> + case KVM_S390_VM_CRYPTO_DISABLE_APIE: >>>> + kvm->arch.crypto.apie = 0; >>>> + break; >>>> default: >>>> mutex_unlock(&kvm->lock); >>>> return -ENXIO; >>>> @@ -1493,6 +1508,8 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) >>>> case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW: >>>> case KVM_S390_VM_CRYPTO_DISABLE_AES_KW: >>>> case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW: >>>> + case KVM_S390_VM_CRYPTO_ENABLE_APIE: >>>> + case KVM_S390_VM_CRYPTO_DISABLE_APIE: >>> >>> As also replied to the QEMU series, could we indicate >>> KVM_S390_VM_CRYPTO_ENABLE_APIE (and maybe >>> KVM_S390_VM_CRYPTO_DISABLE_APIE) only with ap_instructions_available(), >>> so we can avoid the additional KVM_S390_VM_CPU_FEAT_AP? >>> >>> KVM_S390_VM_CPU_FEAT_AP is right now completely unused in KVM otherwise >>> (never checked, we only care about apie). >> >> After much discussion with Halil and a few exchanges with you, we >> decided to go ahead and accept your suggestion to get rid of >> KVM_S390_VM_CPU_FEAT and keep the VM device attributes to enable/disable >> apie. >> >> To that end, I responded to patches 03/26, 11/26 and 25/26 with fixup! >> patches that show the KVM/kernel changes that will be necessary to get >> rid of KVM_S390_VM_CPU_FEAT and use apie to control ECA.28. I did that >> to generate discussion in v10 rather than waiting until v11 for >> comments. I make no guarantees that those fixup! patches will >> successfully apply should you have a v10 branch generated from this >> patch series you want to update. >> > > Will you also fixup this patch to expose KVM_S390_VM_CRYPTO_ENABLE_APIE > only if supported by HW? (ap_instructions_available) Given that this patch DOES expose KVM_S390_VM_CRYPTO_ENABLE_APIE only if supported by HW, I assume you are talking about KVM_S390_VM_CRYPTO_DISABLE_APIE. I didn't check ap_instructions_available() for disabling APIE because I didn't think it necessary given that ECA.28 will be set to 0 (intercept) by default, whether AP instructions are installed or not; so why not allow disabling apie. I suppose from the perspective of consistency, since the kvm_s390_vm_has_attr() function checks ap_instructions_available() for both attributes, then it probably makes sense to add that check to KVM_S390_VM_CRYPTO_DISABLE_APIE here. Then again, we could make a change in ap_instructions_available() to allow KVM_S390_VM_CRYPTO_DISABLE_APIE regardless of whether AP instructions are available. It boils down to whether APIE needs to be dynamically disabled at some point when it has been enabled. The only case I can think of where that may be necessary is if a guest is migrated to a system without AP instructions. I don't think that can happen and may even be protected against precisely because the VM attributes won't be available on the target system due to no AP instructions. What say you? >